graid5 or gvinums - bootable?

[Ulf Lilleengen]

On Sat, Aug 11, 2007 at 10:08:07PM -0500, CyberLeo Kitsana wrote:
> Howard Goldstein wrote:
> > Q: Should a graid5 or gvinum provider be expected to be bootable,
> > assuming the prover's partition table has an active bootable partition
> > containing a properly bsdlabeled 'a' slice with the /boot subdirectories
> > in it (i.e., all of the stuff you normally need in an ordinary, non-geom
> >  system to have a bootable slice)?
> > 
> > Teh googling is somewhat helpful indicating that the boot loader can now
> > deal with the GEOM'd gvinum as the boot device, and of course it works
> > with gmirror but that's not really surprising since that provider
> > wouldn't doesn't have its /boot slice striped into ribbons across
> > multiple consumers like graid5 and gvinum in raid-5.
> 
> I haven't tried with just /boot, but I have a machine with a 1.5GB
> mirror across four disks for the root filesystem, with a graid5 across
> the remaining space for the other filesystems. That works just fine.
> 
> As far as I know, however, no boot loader can understand
> software-striped or software-raid5ed filesystems, given that it would
> essentially need to implement the relevant geom providers itself.
>
Yes. This is no problem with mirrors, since it's essentially just to read the
first sectors of it. However, the other reason is that gmirror stores it's
metadata at the end, so the loader won't have to care about it. So, booting of a
gvinum volume will not work, but using another partition for /boot, and gvinum for
root should work.
-- 
Ulf Lilleengen